Impact of pluronic type on the physicochemical properties of lecithin liposome/pluronic particles

This study investigated how the ethylene oxide (EO) content in pluronic (70% for pluronic F127 and 80% for pluronic F108) affects the physicochemical attributes of lecithin liposome/pluronic particles characterized by a core/shell configuration. Additionally, their ability to encapsulate proteins was examined. Regardless of the EO content, the particles consistently exhibited a core/shell structure up to a lecithin/pluronic ratio of 0.2, with sizes ranging from 230 to 280 nm. Although liposome/pluronic particles maintained stability against pH alterations at 5 °C, storage above this temperature compromised their stability. This suggests that the EO content in pluronic does not significantly dictate the stability of these liposome/pluronic particles. Furthermore, these particles were able to encapsulate a model protein with a low isoelectric point (pI) with relative ease. However, attempts at modifying the liposome surface charge to a positive state for encapsulating proteins with higher pI values did not yield particles with a core/shell structure.